Capturing and saving frames from a webcam
Pressing space saves the current image from the webcam with an increasing counter in the filename, esc exits the loop and script.
import cv2
cam = cv2.VideoCapture(0)
# type(cam) # cv2.VideoCapture
cv2.namedWindow('frame-out')
cnt = 0
while True:
ret, frame = cam.read()
# type(ret ) # bool
# type(frame) # numpy.ndarray
# frame.shape # (height, width, nof-colors) -- nof-colors likely to be 3
cv2.imshow('frame-out', frame)
if not ret:
break
keyPressed = cv2.waitKey(1)
if keyPressed % 256 == 27:
# ESC pressed: exit loop
break
elif keyPressed % 256 == 32:
# SPACE pressed: save image
img_name = f'/tmp/cv2-capture-{cnt}.jpg'
cv2.imwrite(img_name, frame)
print(f'{img_name} written')
cnt += 1
cam.release()
cv2.destroyAllWindows()